The invention relates to a fuel injection nozzle with additive injection for Diesel engines, as generically defined hereinafter. In Diesel engines, in order to vary the course of injection so as, to increase running smoothness and reduce the emission of nitrogen oxides, it is known from German Patent 925 139 to inject the fuel into the combustion chamber in two chronologically separate periods, and to inject an additive, such as water, into the combustion chamber in between the two fuel injections. The known injection nozzle for performing this method has an antechamber to partition off the preinjection quantity and a pressure chamber, into which the inlet conduit for the fuel and the inlet conduit for the additive discharge (FIG. 4), or an annular conduit that joins the additive inlet bore to the fuel inlet bore (FIG. 3). During the injection phase, a quantity of additive is forced into the pressure chamber or into the inlet bore and temporarily stored there. During the injection phase, after positive displacement and injection of the preinjection quantity, the temporarily stored quantity of additive is then injected by fuel pumped at high pressure into the combustion chamber, prior to the injection of the main injection quantity.
An essential feature is that the separation between the injection of the preinjection quantity that initiates ignition, the injection of the additive, and the injection of the main injection quantity be replicable.